The present invention relates to electroluminescent polymer compositions and processes for the preparation and use thereof in, for example, electroluminescent devices such as electroluminescent displays and electrochemical cells.
More particularly, the invention relates to polymer compositions and to processes for making and using in, for example, high performance, that is, high stability and high luminosity electroluminescent displays and devices.
The present invention, in embodiments, is directed to processes for preparing soluble poly(p-arylene vinylene) polymers, especially poly(p-phenylene vinylene) polymers, wherein at least one solubilizing side chain or substitutent is present in the monomer imparts desirable solubility and processibility properties to the resulting polymer product. The present invention is also directed toward polymerization processes for controlling the molecular weight of the polymers, the functionality on the polymer chain ends, and polymer architecture using chain end controlling additives, which controlled factors contribute to improved stability and performance of light emitting devices constructed therefrom. By adjusting the ratio of a chain end controlling additive to a monomer, it is possible to control the molecular weights of the polymer. The higher the ratio, the lower the molecular weight of the polymer product. In extreme cases, one can prepare oligomeric phenylene vinylenes by using large amount of chain initiating additive(s). The use of chain end controlling additives provides a simple and general method for preparing poly(p-phenylene vinylene) polymers with specific chain end functionality. The chain end controlling additives generally serve to initiate and terminate polymerization and are incorporated in the polymer structure ultimately becoming bound at the ends of the polymer chain. The use of a chain end controlling additives with two or more polymerization initiation and termination site enables the preparation of block, branched, and grafted poly(p-phenylene vinylenes). Highly stable poly(p-phenylene vinylene) light emitting devices can be achieved by controlling the polymer molecular weights, chain ends, and architectures through chain end controlling additives.